In the context of manufacturing fibre-reinforced parts, such as blades for wind power plants, a manufacturing process is typically used wherein a part is moulded in sections, e.g. two halves, usually in open moulds. Later the sections are removed from there respective mould and joined together to form said part.
To prepare the mould, a coating, often referred to as gelcoat, is initially applied onto the interior surface of the open mould.
A gelcoat is a material used to provide a high quality finish on the visible surface of the finished part of a fibre-reinforced composite material. Gelcoats are applied to moulds in the liquid state. They are cured to form crosslinked polymers and are subsequently backed up with composite polymer matrices, often mixtures of polyester resin and fiberglass or epoxy resin with glass, kevlar and/or carbon fibres.
The manufactured component or section, when sufficiently cured and removed from the mould will present a gelcoated surface that is usually pigmented to provide a colored, glossy surface which improves the aesthetic appearance of the component.
When the gelcoat have been applied to the interior surface of the mould, it needs proximately one hour to cure. During that time, and during the application of the gelcoat, the gelcoat emits harmful vapours.
Because of the harmful vapours, a person applying gelcoat is usually feed with fresh air through a mask during the process.
Also the production hall needs to be extra ventilated to evacuate the vapours. This is usually done with expensive and large ventilation systems, which work at full capacity typically only a few hours per day, namely during the time when the gelcoat is applied and when it cures (approximately one hour from application). During this period of time no other production steps can be conducted in the production hall.
If two or more moulds are used the production needs to be coordinated with respect to the gelcoating process, so that valuable mould time is not wasted waiting for gelcoat to be applied in other moulds or ventilation of the production hall.
During the production steps following the application and curing of gelcoat, a number of layers of fibre material are arranged in the mould, typically by hand, and followed by a resin to attach the individual layers of fibre material to each other.